Invader Zim Episode 1 - The Nightmare Begins Episode Title:The Nightmare Begins.Episode Description:The Irken race is having a great assigning for Operation Impending Doom II, where all Invaders are assigned a planet to conquer. Zim is not invited, as he nearly destroyed the planet Irk during Operation Impending Doom I; yet turns up anyway, and hoping to never deal with him again, The Almighty Tallest send Zim on a fake mission to the edges of their known universe and issue him a dysfunctional Standard Information Retrieval unit who called himself "GIR", where they hope he will die/be lost and never found. Unfortunately, there is a planet called Earth on the outskirts of the Irken universe, and when Zim finds this world he assumes this is the subject of his "mission". After arriving on Earth, Zim attempts to fit in and fools everyone except his schoolmate Dib, a young paranormal investigator, who vows to capture Zim and prove that he is an alien.